摘要
根据Fick第二定律建立了硫酸根离子在混凝土中的非稳态扩散反应方程,利用有限差分法求解该方程以获得硫酸根离子在混凝土中的浓度分布规律。根据硫酸根离子与混凝土中铝酸钙盐之间的化学反应所生成钙钒石的数量,给出了钙钒石生成过程中的混凝土膨胀应变计算公式,并由混凝土本构关系计算相应的膨胀应力,以评估混凝土是否开裂破坏。最后,通过数值仿真,模拟浸泡在2%Na2SO4溶液里的混凝土板内的硫酸根离子扩散过程、膨胀应变及应力变化、开裂破坏等全过程。结果表明:所提出的分析方法可定量地描述硫酸盐侵蚀下的混凝土损伤破坏规律。
Based on Fick＇s second law, a nonsteady diffusion equation of sulfate ions, in which chemical reactions depleting sulfate ions in concrete are considered during diffusion, is presented, and the f＇mite difference is applied for solution of the equation to obtain the sulfate ion concentration distribution in concrete. Based on the amount of ettringite produced from the chemical reactions between sulfate and aluminates, the expansion strain due to the growth of the reaction product in concrete is calculated, and the constitutive relation of concrete was used to determine the expansion stress for evaluating the cracking failure of concrete. Finally, numerical simulation is utilized to analyze the process of the sulfate ion diffusion, the increment of the expansion strain and stress and the cracking of a concrete plate immersed into 2% sodium sulfate solution. The results show that the suggested analytical methods can quantify the cracking process of concrete under sulfate attack.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2009年第7期1063-1067,共5页
Journal of The Chinese Ceramic Society
基金
国家"973"计划(2009CB623200)
江苏省自然科学基金(BK2007212)
中国博士后基金(20060400903)
江苏省博士后基金(0602009B)资助项目
关键词
硫酸盐侵蚀
混凝土
化学力学模型
损伤破坏
数值分析
sulfate attack
concrete
chemo-mechanical model
damage and failure
numerical analysis
